MCP SEP-2260 server requests and Sume's tools-only hosted MCP
SEP-2260 lets servers send requests only while handling a client request. Sume's hosted MCP code has no sampling or elicitation requests, so nothing changes.
Sume's hosted MCP server does not start requests to the client on its own, so SEP-2260 needs nothing from you. The 2026-07-28 release candidate says servers may send requests to a client only while processing a client request. We searched the hosted server's source on origin/main and found no sampling or elicitation code.
The rule comes from the release candidate post, alongside a deprecation of roots, sampling and logging (SEP-2577) with a 12-month minimum before removal.
Related changes in the release candidate
| SEP | What the post says |
|---|---|
| SEP-2260 | Server requests only while processing a client request |
| SEP-2322 | InputRequiredResult for multi-round-trip input |
| SEP-2577 | Roots, sampling and logging deprecated; 12-month minimum before removal |
| SEP-2549 | ttlMs and cacheScope |
What this means for a Sume client
Sume's hosted MCP is a tools server: you list tools, you call them, and long jobs finish through jobs_wait with a hold of at most 55 seconds (hosted MCP docs). If jobs_wait returns wait_slice_expired, call it again; never resubmit the paid create.
Because the server never asks the client for a model completion, you do not need to implement sampling in your own client just to use Sume.
Checklist
- Do not build sampling or elicitation handlers only for Sume.
- Treat
wait_slice_expiredas a retry of the wait, not of the job. - Re-check this when the final spec ships; this reflects the release candidate only.
Sources
Related posts
More in Developers
- MCP spec timeline: 2025-11-25, RC on May 29, stable on July 28, 2026
The MCP 2026-07-28 spec went stable on July 28, 2026, 60 days after its May 29 RC, replacing 2025-11-25. Dates, and how to check what you run.
- MCP step-up scopes (SEP-2350) vs Sume's mcp:write re-consent
The MCP 2026-07-28 draft adds step-up scope accumulation. On Sume today, getting from mcp:read to mcp:write means a new consent and a new token.
- MCP tasks/get vs Sume's Agent Completion status_url polling
The MCP 2026-07-28 tasks extension polls by handle with tasks/get. Sume's Agent Completions poll a status_url until next_action is not poll_status.
- MCP tool ran twice: idempotency_key saves your Sume render
Claude Code fixed MCP tool calls that sometimes ran twice on large results. Sume's paid MCP tools require an idempotency_key so a repeat does not bill twice.
Written by Sume